Most of the foreign components were included through public bidding. On this list, most of the foreign components have domestic counterparts. I'm sure there was also some behind the scenes negotiations to purposely include foreign suppliers in order to pave the way for FAA and EASA approvals. The only real showstopper is the engine. The reason there isn't already C919 options for things like the landing gear and tires is because COMAC took the path of least resistance. This is the general trend of development that most of China's high tech projects take. They accelerate development by taking the lowest cost, fastest approach to realize project goals. Then, once the integrated platform is certified, they move towards greater indigenization. This is the general development trend worldwide nowadays. It's only in China's case where analysts focus so much on the indigenous content because it's under such constant sanctions threat, as you suggested.
